Phosphorylated RaIA

Abstract

Antibodies that are specific for human Ra1A that is phosphorylated at one or both of Ser183 and Ser194 are described as various methods such antibodies, including diagnostic methods and screening methods.

What is claimed is: 
     
       1. A method for detecting the presence of a polypeptide comprising SEQ ID NO: 9 in a subject, wherein the polypeptide is phosphorylated at one or both of Ser183 and Ser194, the method comprising:
 (a) providing a biological sample; 
 (b) contacting the biological sample with an antibody or antigen binding portion thereof, wherein the antibody: i) binds to a polypeptide consisting of SEQ ID NO: 9 (RalA) that is phosphorylated at one or both of Ser183 and Ser194; and ii) does not bind to a polypeptide consisting of SEQ ID NO:9 that is not phosphorylated at Ser183 and is not phosphorylated at Ser194; and 
 (c) detecting the presence or absence of a polypeptide comprising SEQ ID NO: 9, that is phosphorylated at one or both of Ser183 and Ser194 bound to the antibody or antigen binding portion thereof. 
 
     
     
       2. A method for detecting the presence of a polypeptide comprising SEQ ID NO: 9 in a subject at two time points, wherein the polypeptide is phosphorylated at one or both of Ser183 and Ser194 the method comprising:
 (a) providing a first biological sample taken from a subject at a first time point; 
 (b) providing a second biological sample taken from the subject at a second time point after the first time point; and 
 (c) contacting each of the first and the second biological samples with an antibody or antigen binding portion thereof, wherein the antibody: i) binds to a polypeptide consisting of SEQ ID NO: 9 (RalA) that is phosphorylated at one or both of Ser183 and Ser194; and ii) does not bind to a polypeptide consisting of SEQ ID NO:9 that is not phosphorylated at Ser183 and is not phosphorylated at Ser194; 
 (d) detecting the presence or absence of RalA or a polypeptide comprising SEQ ID NO: 9, that is phosphorylated at one or both of Ser183 and Ser194 bound to the antibody or antigen binding portion thereof in each of the first and second biological samples. 
 
     
     
       3. The method of  claim 1  or  2  wherein the isolated antibody molecule or antigen binding portion thereof binds to a polypeptide comprising SEQ ID NO: 9 that is phosphorylated at both Ser183 and Ser194. 
     
     
       4. The method of  claim 1  or  2  wherein the antibody molecule or antigen binding portion thereof is a recombinant antibody molecule or antigen binding portion thereof. 
     
     
       5. The method of  claim 1  or  2  wherein the antibody molecule or antigen binding portion thereof has a dissociation constant (K d ) for the polypeptide consisting of SEQ ID NO: 9 that is phosphorylated at one or both of Ser183 and Ser194 in the range of 10 −6  M to 10 −12  M. 
     
     
       6. The method of  claim 1  or  2  wherein the antibody molecule or antigen binding portion thereof is detectably labeled.